Moving from Virtual Server 2005 R2 SP1 to Hyper-V involves migrating both the Virtual Server host and the virtual machines. This chapter from Windows Server 2008 Hyper-V Resource Kit will provide you with guidance about what should be moved, how to move it, when to move it, and other important considerations you need to be aware of during the process.

Moving from Virtual Server 2005 R2 SP1 to Hyper-V involves migrating both the Virtual Server host and the virtual machines. Because of the change in architecture, it is not a simple process—you can’t perform an upgrade in place to make this move. Rather, the host and virtual machine migrations must be done separately. It is not a terribly difficult process, but the multiple steps involved in the migration must be performed in the correct order. This chapter will provide you with guidance about what should be moved, how to move it, when to move it, and other important considerations you need to be aware of during the process.

Virtual Server 2005 R2 SP1 is a hosted virtualization solution that runs on top of the operating system, and Hyper-V is a hypervisor that runs under the operating system. Because this is a significant change in architecture between Virtual Server 2005 R2 SP1 and Hyper-V, there is no option to perform an in-place upgrade of a Virtual Server 2005 R2 SP1 to Hyper-V.

The goal of the migration should be to get the Virtual Server host and virtual machines migrated with minimum impact and downtime. The best way to accomplish this is to migrate to new server hardware. This allows you to install Windows Server 2008 and the Hyper-V role or Microsoft Hyper-V Server 2008, configure the machine for the migration, and properly optimize the configuration following the guidelines provided in Chapter 7, “Hyper-V Best Practices and Optimization.” After you have optimized the installation, the virtual machines can be migrated from the Virtual Server 2005 R2 SP1 server to the new Hyper-V server.

Maintaining Virtual Server 2005 R2 Hosts

Although you might be tempted to migrate off all Virtual Server 2005 R2 SP1 hosts, it is a good idea to keep Virtual Server around for certain guest operating systems. Virtual Server 2005 R2 SP1 provides support for the following guest operating systems that Hyper-V does not support:

Windows NT Server 4.0 with Service Pack 6a

Windows XP SP2 (for Virtual Server 2005 R2 only)

OS/2 4.5

Red Hat Enterprise Linux 2.1 (update 7)

Red Hat Enterprise Linux 3.0 (update 8)

Red Hat Enterprise Linux 4.0 (update 4)

Red Hat Enterprise Linux 5.0

Red Hat Linux 9.0

SuSE Linux 9.3

SuSE Linux 10.0

SuSE Linux 10.1

SuSE Linux 10.2

If you have virtual machines running any of these guest operating systems, we would recommend keeping them on Virtual Server instead of moving them to Hyper-V.

Wireless Networking Support

Virtual Server 2005 R2 SP1 provides support for wireless networks to be used for binding virtual networks. Hyper-V does not implement direct attachment of external virtual networks to wireless network adapters because Hyper-V adheres strictly to the 802.11 specifications, and those specifications do not allow wireless networks to modify the MAC address.

Server Hardware Support

You must evaluate your hardware before upgrading to Hyper-V to manage your virtual machines. The hardware you are planning to use for the Hyper-V server must be 64-bit and must provide hardware virtualization extensions enabled for the Hyper-V installation to be completed successfully. Since you cannot upgrade an existing Virtual Server 2005 R2 SP1 server directly to Hyper-V, either you must provide new server hardware, or the existing hardware must meet the recommended minimum Hyper-V hardware specifications to be reused.

Minimizing Downtime

When you migrate virtual machines from Virtual Server to Hyper-V, the virtual machines must be powered off for the migration. This will cause a period of downtime for the individual virtual machines. In addition, depending on the approach you take during the migration of the Virtual Server host, the host also could experience downtime that will result in downtime for all the virtual machines. Therefore, you should determine how much downtime is acceptable for the host and the virtual machines before you choose the host migration approach.